Apparatus for corrugating metal tubes



Dec. 8, 1931. L. L. LORD APPARATUS FOR CORRUGATING METAL TUBES 2 Sheets-Sheet 1 Filed Jung 20, 1928 Y 7. 2 I 1 ea W7 35 A m 6 556 Z D u wum wz.

w Inventor.-

De. 8,1931. L. LORD 1,835,314

APPARATUS FOR CORRUGATINGMETAL TUBES Filed June 20, 1928 2 Sheets-Sheet 2 ltTgJ.

r n m Patented Dec. 8, 193 1 UNlTED STATES PATENT OFFICE LYMAN L. LORD, OF BOSTON, irassacnusnr'rs, assrenon' 'ro E. B. Banana & sons'coni- PM, or BOSTON, msacnu'snrrs, A coaromrron or MASSACHUSETTS I APPARATUS FOR coanuea'rme TUBES Application filed June 20, 1928. Serial n... aaasao.

This invention relates to apparatus for 'corruga ting metal tubes and more particularly to apparatus of the type'embodying relatively movable corrugated die or mold sections adapted'to be applied to the outside of the tube, after which the tube issubjected at the same time to end pressure longitudinal ly and to internal fluid pressure, the object of the invention being to facilitate the forming )0 operation and to provide devices quickly and readily applicable to and removable from the tubes and designed to cooperate with themeans through which the end pressure and internal pressure are applied to prevent leakage during the several steps performed in' the functioning of the apparatus.

In carrying out the operation above referred to, as, for example, in the formation of corrugated expansion jointsfor steam or hot water lines, a cylindrical metallic tube is placed with its ends in abutting relation to two separated and opposing heads which are capable of being forced relatively toward each other to provide the end pressure re ferred to. Means are also provided to admit hydraulic orother fluid pressure to the interior of the tube so that, as the tube is contracted under the end pressure, the internal pressure causes it to expand inexact conformation to the internal formation of the die or mold sections which are initially located at suitable, spaced distances apart but approach ceeds. V

One object of the present invention is to provide an end closure which can be readily applied to the tube prior to its installation in the apparatus and preferably without the I to engage the walls of the tube and theipipe or conduit through which fluid pressure is admitted thereto orto pack. the end of the tube and to prevent'leakage therefrom. v The inventionwill be best understood by referenceto the following description when each-'otheras the forming operatlon pro-- to be placed with itsends in;

as apart of the machine itselfautom'atically taken in connection with the accompanying illustration of one specific embodiment thereof, while its scope will be more particularly pointed out in the appended claims.

In the drawings Fig. 1 is a sectional elevation showing the apparatus for forming corrugated metal tubes embodying one form of the invention, the tube being shown in its relationship to the machine as initially installed therein;

Fig. 2 is a view showingthe relationship of the parts after fluid pressure has been admitted to initially set the tube against the surrounding dies;

Fig. 3 shows the relationship of the parts after the corrugated formation of the tube has been completed; 7

Fig. 4 is a cross sectional elevation taken through one of the sectional die members;

Fig. 5 is an end'elevation of one of the end closures on an enlarged scale; and

Fig. 6 is a sectional elevation taken through the same end closure showing its relationship to the tube when in position comprisesthe bed plate'llon which there is provided at one end the upright stationary head 13 and at the opposite end the head 15, the latter serving as aguiding sup ort for the horizontally moving plunger 1 carrya ing the movable head 19,-.between which and the stationary head 13 the tube 21 is adapted tion to each.

The plunger 17 and head 19 are'capable of being moved toward the stationary head.

13 under a pressure sufficient to collapse the largest and heaviest'tube to be cor-.

rugated, and the power employed for this purpose may be elther hydraulic or other fluid pressure or mechanical power transmitplunger 17. through appropriate ted to the gearing. The two stationary heads 13 and 15 are connected by four or more tie rods 23 which are located outside of the space occupied by the. mold or die sections, the movable head abutting rela- 19 being slidably related to such tie rods. The stationar heads are also connected by two other ro s 25 which pass through the movable head and through the lower half of each mold section and serve as supports therefor as well as guides for the individual mold the . the upper half 29. After the tube has been positioned in the machine, the upper half of each mold section is clamped to the lower half by means of bolts 33 which are pivoted at 35 in the slotted ends of laterally projecting lugs 37 on the lower half of the mold, the bolts being swung up to enter the open ends of the similarly slotted lugs 39 presented by the upper half 29 and clamped tightly in position by means of the nuts 41. The upper half of each section can be readily removed after the formation of the tube by loosening the nuts 41 and swinging the bolts back and down out of engagement.

The mold sections (Figs. 1 to 3) comprise the end sections 29 which are each shaped to form one-half of an end corrugation of the tube. leaving the portion of the tube projecting beyond the end corrugation in finished cylindrical shape and of its original diameter. The mold sections also comprise other intermediate sections 29 shaped each to form a complete intermediate corrugation, so that when the tube is completed and the die sections are brought into contacting relation (as shown in Fig. 3) they provide a sectional moldwhich is a true matrix of the corrugated tube required to be formed. The shape and dimensions of the corrugations may be varied. within wide limits and the number of corrugations may be varied by increasing or decreasing the number of intermediate mold sections, there being herein shown for purposes of exemplification two intermediate die sections 29 for the formation of a tube with three corrugations.

To apply fluid pressure internally within the tube during the process of formation any suitable means may be employed, but herein there is provided a, pump 43, diagrammatically shown in Fig. 1, connected to supply water or other fiuid under pressure to the interior of the tube 21 by means of a pipe 45 which passesthrough the stationary head 13. Means are preferably provided to supply fluid pressure of any desired amount and to regulate the same, there being herein shown for this purpose, and as exemplifying such devices. the manually operated valve 47 for controlling. the supply from the pump, the

manually operated relief valve 49 by which the pressure may be manually relieved, and the automatic relief valve 51 of any desired type which may be set to keep the pressure automatically at some desired limited amount. A pressure gauge 53 is also provided by means of which the operative can be advised of the fluid pressure within the tube.

To close the end of the tube against leakage, an end closure is provided (see Figs. 5 and 6) comprising the disk-like plate 55, preferably of rubber or other like compressible material, clamped by means'of the clamping bolts 57 between an inner metallic backing disk 59nand an outer circular face plate 61. The rubber plate is of such a size that in its normal condition, when uncompressed. it can be forced into the end of the tube 21, the backing plate and face plate being of lesser diameter than the inside diameter of the tube. The end closure for the end of the tube abutting against the movable head 19 is imperforate, while the closure for the opposite end of the tube is provided iwth the central perforation 63 of such size as to cause the rubber to grip tightly about the walls of the fluid supply pipe 45 when the tube with its end closure is placed in position in the machine. The outer side of the face plate 61 is provided with a series of ribs 65 providing seating walls which, when brought flush with the end of'the tube, cause the rubber to engage the inner walls of the tube at a substantial distance from the end of the tube, so that, for an object hereinafter explained, a substantial outward movement of the end closure relatively to the tube may take place without causing the rubber to disengage from the inner walls of the tube.

In the use of this apparatus an imperferate end closure is installed in one end of a cylindrical tube blank (see Fig. 1) and a centrally perforated end closure, of the type shown in Figs. 5 and6, is installed in the opposite end of the tube. The end closures are installed by forcibly pressing the rubber disks into the ends of the tubes far enough to bring the edges of the seating ribs 65 approximately flush with the ends of the tubes. After the end closure has been forced into the tube, the bolts 57 may be set up tightly if desired to compress the rubber plate and expand it into closer fitting contact with the inner walls of the tube.

The upper halves 29 of the several die sections having been removed and the movable head- 19 retracted, the tube is then placed in the machine resting on the lower halves 27 of the die sections, the perforated end closure being forced over the end of the fluid pressure supply pipe 45. The movable head 19 is then moved up to bring the ends of the tube in abutting relationship to the two heads 13 and 19 and the upper halves of the die sections placed loosely in position on the lower halves. The die sections are then separatedby spaced intervals such as 'toleave the required amount of metal between their respec tive points of contact to form the final correin various ways, but preferably the valve 47 'is opened to fillthe interior of the tube with -1 fluid, after which, and before applying powerto move the head 19 longitudinally, the fluid pressure is brought to a point sufficient to ex pand the tube into firm seating contact against the silrrounding dies.

The internal pressure thus exerted against each end closure forces the faceplate 61 into 1 close seating contact with the corresponding 7 head 13 or 19,- compressing therubber disk between the face plate and the backing plate, causlng it to further expand and forcibly engage the inner walls of the tube', securing the effect of a tightly packed piston capable of preventing leakage under the highest pressure usable in practice. At the same time the compression' of the rubber plate causes the rubber in the'end closure abutting against the head 13 to grip tightly about thep'pe 45, similarly preventing leakage at that point,

this point, the operative preferably increases Having brought the fluid pressure up to v the internal pressure to efi'ecta slight and shown in possibly exaggerated form in Fig. 2.

barely visible initial set in the tube, which is This is required to be only such as will defin tely position the contacting diesections with relation to the outer walls ofthe tube,

so that in the subsequent contracting opera tion they approach each other while maintaining the same definite relationship to their initial setting points on the tube.

This initial set tends to shortenthe longitudinal dimension of the tube and to withdraw one or both ends from its abutting relationship to the adjoining head. When this takes place, however, the end closure under the internal fluid pressure maintains the same seating relationship to the head and being relatively movable within the tube, the latter contracts longitudinally with relation to the, end closure which, however, continues to function as an eflicient packing for the tube.

, This condition is represented in Fig. 2'. When this point is reached,'power is applied to move the head 19 to apply longitudinal end pressure, thereby forcing the tube outwardly into and against the contoured die sections to form the corrugations until the. condition represented in Fig. 3 is reached, the internal fluid pressure being" preferably maintained throughout this operation either by means of the manually actuated relief vave 49 or the automatic relief valve 51 at substantially the pressure which was employed in securing the initial set. As soon as the head 19 is moved ends of the tubes are again brought into abut "to apply the longitudinal end pressure, the.

ting contact with the respective heads'jand' again move relatively tothe-end closures, the

latter continuing to function as before under the influence of the internal pressure to efliciently close and pack the ends of the tubes.

During the longitudinal contraction of the tube and the radial expansion of portions thereof the die sections 27 and 29 approach Y each other, and, after the heads and the dies have been'brought to'the relationship represented in Fig. 3, where the die sections have cut off from the movable head, the internal fluid pressure relieved and-the relief valve 49 opened to drain or partially drain the water from the inside of the formed tube. The head 19 is then retracted, the upper die sections removed, 'the .corrugated tube withdrawn from the machine, and the end closures removed, their removal being facilitated, if required, by loosening the clamping bolts 57 While Ihave' herein shown anddescribed for'purposes of illustration one specific einbod'iment of the invention, it is to be understood that extensive deviations may be made therefrom without departing from the spirit thereof. V

Claims:

1. An apparatus for corrugating metal tubes having relatively movable corrugated mold, sections adaptedto be applied to the outside of the tube, means for applying end 7 pressure longitudinally to the tube compris ing opposing heads between which the tube may be placed with its ends in abutting rela-" tion to each with means for forcing said heads relatively toward each other, means for supplying pressure fluid to the interior of the tube to expand the tube from within, and

an end closure for the tube adapted when in the tube to abut'against one of said heads,

lbeen brought into close contact, the power is a said pressure fluid supplying means includingra pipe-also passing through said end closure, said closure being relatively inov-- able withinfthe tube and self expanding under the internal fluid pressure therein while abutting against said head to forcibly engage the inner walls of the tube and the outer walls of said pipe to prevent leakage.

2. An apparatus for corrugating metal tubes having relatively movable corrugated mold sections adapted to be applied to the outside of the tube, means for applying end pressure longitudinally of .the'tube comprising opposing heads between which the tube may be placed with its ends in abutting relation to each, means for forcing said heads relatively toward each other, means for sup- ;plving pressure fluid to the interior of the tube to expand the tube from within, and an end closure for the tube adapted when in the tube to abut against one of said heads, said closure being relativelymovable within the tube and self expanding under the internal pressure therein while abutting against said head to forcibly engage the inner walls of the tube.

5 3. An apparatus for corrugating metal tubes having 'a corrugated mold adapted to be applied to the outside of the tube, means for applying pressure longitudinally to the tube comprising opposing heads between which the tube may be placed in abutting relation to each, means for supplying fluid pressure to the interior of the tube, and an end closure adapted to fit the interior of the tube and to abut against one of said heads,

said closure being relatively movable within the tube and self expanding under the internal pressure thereinto forcibly engage the inner walls of the tube.

4. A machine for corrugating metal tubes having a corrugated mold adapted to be applied to the outside of the tube, means for applying end pressure longitudinally to the tube, and means for supplying pressure fluid to the interior of the tube, the machine ineluding an end closure for the tube frictionally engaging the inner walls of the tube and self expanding under the internal fluid pressure within the tube to forcibly engage the inner walls of the tube and prevent leakage therefrom.

5. A machine for corrugating metal tubes having means for applying end pressure longitudinally of the tube comprising a station'- ary head and a movable head, and a pipe passing through the stationary head to the I gitudinally of the tube comprising a station- ,ary head and a movable head, and a pipe passing through-the stationary-head to the interior of the tube to supply fluid pressure thereto, including an end closure for the tube 'frictionally engaging the inner walls thereof and compressible under the internal pressure to forcibly engage the inner walls of said tube and the outer walls of said pipe to prevent leakage therefrom, the same comprising a face plate having seating walls adapted to engage one of said heads, a disk I of yieldable material the periphery of which frictionally engages the inner walls of the tube, and a backing plate between which and the face plate the yieldable disk is secured.

' 7. A machine for corrugating metal tubes having relatively movable corrugated mold sections adapted to be applied to the outside of the tube, means for applying end pressure longitudinally of the tube comprising opposing heads between which the tube may be placed in abutting relation to each, means for forcing said heads relatively toward each other, and means for supplying fluid pressure-to the interior of the tube, the machine including end closures frictionally engaging the inner walls of the tube and adapted to abut against the respective heads. a

8. A machine for corrugating metal tubes having relatively movable corrugated mold sections adapted to be applied to the outside of the tube, means for-applying end pressure longitudinally of the tube comprising op posing heads between which the tube may be placed in abutting relation to each, means for forcing said heads relatively toward each other, and means for supplyin fluid pressure to the interior of the tube, t e machine including cylindrical end closures fitting the opposite ends of the tube to pack the same against leakage, saidclosures being relatively movable in the tube.

9. A machine for corrugating metal tubes having'relatively movable corrugated mold sections adapted to be applied to the outside of the tube, means for applying end pressure longitudinally of the tube comprising opposing heads between which the tube may be placed in abutting relation to each, means for forcing said heads relatively toward each other, and means for supplying fluid pres-.

sure to the interior of the tube, the machine including an end closure within the end'of the tube adapted to be forced into engagement with the walls of the tube underthe internal pressure within the same to pack the same against leakage.

10. A machine for corrugating metal tubes havingrelatively movable corrugated mold sectionsadapted to be applied to the outside of the tube, means for applying end pressure longitudinally of the tube comprising opposing heads between which the tube may be placed in abutting relation to each, means for forcing said heads relatively toward each other, and means for supplyin fluid pressure to the interior of the tube, the machine including an end closure fitting the interior of the tube and comprising a disk of yieldable material, a backing plate and outer face plate having expanding seating walls adapted to seat against the abutting head.

11. An apparatus for corrugating metal tubes having relatively movable corrugated mold sections adapted to be applied to the outside of the tube, means for applying end pressure longitudinally'to the tube compris- 'ing opposing heads between which the tube may be placed with its ends in abutting relation to each with means for forcing the heads relatively toward each other, means for supplying fluid pressure to the interior of the tube to expand the tube from within, and an end closure for the tube disconnected from said heads and applicable to the tube prior to its installation in'the machine, said end closure reventing leakage from the tube during t e corrugating operation. 12. An apparatus or corrugating metal tubeshaving relatively movable corrugated mold sections adapted to be applied to the. outside of the tube, means for applying end pressurelongitudinally to the tube comprising opposed ,relatively movable heads between which the tube may be placed with its ends in abuttin relation to each with means for forcing sai heads relatively toward eachother, means for applying pressure fluid to v the interior of thetube to expand the tube from within, and pressure tight (packing means engaging the walls of an en of the 7 tube to prevent-aleakage therefrom, said packing means permitting relative movement between the'tube and the adjoining head i when the tube is shortened by preliminary application of internal pressure.

13. A machine for corrugating metal tubes having relatively movable, corrugated, mold sections adapted to be applied to the outside of the tube, means for applying end pressure longitudinally .to the tube comprising opposed, relatively movablejheads between which the tube may'be placed with its ends in abutting relation to each, means for sup- :0 pl ing pressure fluid to the interior of the tube to expand the tube from within andshorten it longitudinally, and means for closing an endof the tube to revent leakage therefrom when the tube is s ortened by pre- 3 liminary application of internal pressure and an end thereof caused to withdraw from the adjoining head, said 'means comprising an end closure for the tube. frictionally engaging. the inner walls thereof torevent leakage 4o therefrom, said end closure ing relatively movable within the tube.

In testimony whereof, I have signed my I name to this specification. LYMAN L. LORD. 

